Electron discharge device



Feb. 1, 1949. s; CSZIKLAI ELECTRON DISCHARGE DEVICE Filed Sept 6, 1945INVENTOR 65am? 6. Sz/KM/ 'ATTORNEY Patented Feb. 1, 1949 I STAT ZAQAELECTRON DISGHARGE DEVICE George (1. Szilglai, Princeton, N. 3.,assignor to Delaware Radio Corporation of America, a corporation ofApplication September 6, 1945, Serial No. 614,692.

7 Claims. (Cl. 3156) 1 Myinventionrelates to electron discharge deusefulat ultra high frequencies and more ularly to such. devices employingvelocity In 192? 9? inductive Output and utilizing r ts: monsters.

The prir "pal'object ofrny invention is to provides; velocity modulatedoscillator capable of deliver e. man owe at high. f e s an with improvedefficiencies, and to the methods for mod la i sai de i s- Thenovel'features which I believe to be characteristic of my invention are setforth with arti ularity n. tbeapnc cls c aim but the vehtion;it's ifwill best be understood. by reference to; tb fql ow ne des i ti n takein onn w th th accom an n draw w h Figure I is a sche atic longitudinalsection of an electron disohargedevice made according to my inveni cnand F gure 21. a dia ramma n tu dinal section of a modification oi thedevice sh n 11 F ure 1 I In accordance wtih my. invention the electrondisc r de c is pr ide i an on e envelope H3" having: a transverse oiTsetportion "l' Mounted a ne ta of en e e is an nd qtl'y' heat a anode. u abe m m n electrode i2; electrons being directed toward a collector It atthe other end of the envelope. Positioned intermediate the cathode andcollector is an electromagnet ltffor providing a magnetic fieldtransverseto the path of the beam of electrons. As a resultof this fieldthe electrons take the curved path indicated and. are directed towardreflecting electrode M" passing through the resonator l6 and beingreflected back along the dotted path. tolthe; magnetic. field whichcauses the electron path to reverse itself and be directed toward thecollector l3. The beam on passing through the grids l6 ofthe resonatort6; issub- ,i'ected to av-elocit-y modulation, becomes-bunched and;passing through the resonator again, maintains'the resonator inoscillation, causing this portion of the device to act in the manner ofa reflex oscillator or as a space charge grid Barkhausen oscillator,

i The bunched electrons then pass through the grid H of the resonatorl'l inducing a high frequency voltage in this resonator, which in turnvelocity modulates the beam again, thus accentu" ating the bunching. Thebeam then is directed through the grids l8 of the resonator l8, energybeing extracted in a manner now well known. The electrons are thencollected by the collector l3. A'coupling loop 30 may be used forextracting energy in the usual manner.

Thevoltagesourcesis, 20 and 2!. are provided ior applying the propervoltages to the various electrodes, the resonators- Hi, il and #8 beingmaintained. at high positive potentials, the reilector. H5, beingproperly biased to reflect the electrons as described above, thecollector i 3 being maintained at a lower positive potential for re".ceiving the electrons.

Since the same beam. current is used in all stages, higher. efficiencymay be obtained than in conventional oscillators utilizing cavityvresona: tors. The cascade amplifier portion,..particularly the resonatorll, acts as a. bufier and prevents interaction between the outputresonator section it and the oscillator section !6. By use of themagnetic field the. combination or" the oscillator and amplifiersections is made possible with the result that theinput power. maybematerially reduced it is also obvious'that by. changing the potentialof the reflector M within limits the oscillator rnay be frequentlymodulated. Thus the output off the devicemay be. frequently modulated yth sam iece y In order to amplitude modulate the device the beam currentpassing the last resonator it must be varied. Thisvariation, however,must be' effected after the beam passes through the oscillator,otherwise frequency modulation will occur simultaneously. A deviceforaccomplisb ing amplitude mqdulationis disclosedinF-igure 2.

In Figure 2 like numerals refer to like parts as in Figure 1', theamplifier section alone being different. The beam after being velocity,modulated by the oscillator portion of the envelope passes through thebufier stage ll and'entersthe deflection field between deflecting platesand Z3, deflecting the beamacross the aperture or gate 2*! in theapertured plate 2E; the amount of deflection determining the beamdensity and hence the output current. The amount of current pass.-ingthrough the gate or aperture isdetermined by the amplitude of thepotential applied to the deflecting plates 22, 23. In order tostraighten the beam after passage through the aperture 24, a second setof deflecting electrodes 25 and 26 are provided, these deflectingelectrodes being crossconnected with the plates 22 and 23 so that thesame potential is applied twice but in opposite directions to straightenout the beam path. The device shown in Figure 2 possesses all of theadvantages of the device shown in Figure 1.

While I have indicated the preferred embodiments of my invention ofwhich I am now aware and have also indicated only one specificapplication for which my invention may be employed,

it will be apparent that my invention is by no means limited to theexact forms illustrated or the use indicated, but that many variationsmay be made in the particular structure used and the purpose for whichit is employed without departing from the scope of my invention as setforth in the appended claims.

What I claim as new is:

1. An electron discharge device having cathode means for directing astream of electrons along a beam path, an electrode in said path towardwhich said electrons are directed, means for deflecting said stream atan angle to said path, means for velocity modulating said deflected electrons and returning said electrons along said first path toward saidelectrode, means for further velocity modulating said returnedelectrons, and means for extracting energy from said velocity modulatedelectron stream.

2. An electron discharge device having a cathode for directing electronsalong a predetermined path, means for generating a magnetic fieldtransversely to said path for causing said electrons to be deflectedfrom said path, means for velocity modulating said deflected electronsand for directing said electrons back toward said path including a firstresonator and a reflecting electrode, a second resonator in the path ofsaid electrons for further velocity modulating said electrons, a thirdresonator for extracting energy irom said electrons, and a collector forsaid electrons,

3. An electron discharge device having a cathode for directing electronsalong a predetermined path, an electrode toward which said electrons aredirected, means for generating a magnetic field transversely to saidpath ,for causing said electrons to be deflected from said path, meansfor velocity modulating said deflected electrons and for directing saidelectrons back toward said path including a first resonator and areflecting electrode, a second resonator in the path of said electronsfor further velocity modulating said electrons, and a third resonatorfollowing said second resonator for extracting energy from saidelectrons.

4. An, electron discharge device having an elongated envelope and anoffset portion transverseto said elongated portion, a cathode at oneendof said electrode and a first electrode at the other end of saidenvelope, said cathode directing electrons toward said electrode, meanspositioned adjacent said envelope for directing a magnetic fieldtransversely to said electron path at the transverse portion of saidenvelope, a refleeting electrode at the end of said offset portiontoward which said electrons are directed, a first resonator positionedbetween said reflecting electrode and the means providing saidelectromagnetic field, and other resonator means positioned between saidfirst electrode and the transverse portion of said envelope, andincluding a second resonator for velocity modulating said electronstream and a third resonator for inductively extracting energy from saidvelocity modulated electrons.

5. An electron discharge device having cathode means for directing astream of electrons along a beam path, a first electrode in said pathtoward which said electrons are directed, means for deflecting saidstream at anangle to said path, means for velocity modulating saiddeflected electrons and returning said electrons along said first pathtoward said first electrode, and means for further velocity modulatingsaid returned electrons and further means for extracting energy fromsaid velocity modulated electron stream, and means for amplitudemodulating said electron stream and including a pair of deflectingelectrodes positioned between said last two means.

6. An electron discharge device having cathode means for directing astream of electrons along a beam path, a first means in said path towardwhich said electrons are directed, means for deflecting said stream atan angle to said path, means for velocity modulating said electrons andreturning said electrons along said first path toward said first means,resonator means for further velocity modulating said electrons and otherresonator means for extracting energy from said velocity modulatedelectron stream, and means for amplitude modulating said electron streamand including a pair of deflecting electrodes positioned between saidlast two resonators.

7. An electron discharge device having cathode means for directing astream of electrons along a beam path, a first means in said path towardwhich said electrons are directed, means for deflecting said stream atan angle to said path, means for velocity modulating said elecirons andreturning said electrons along said first REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,450,265 Slepian Apr. 3, 19232,081,429 Gaede May 25, 1937 2,272,165

Varian et a1 Feb. 3, 1942

